Bag



T. E. PIAZZE March 1, 1956 BAG Original Filed Jan. 11, 1962 2 Sheets-Sheet 1 THOMAS E. PIAZZE T. E. PlAZZE March 1, 1966 BAG 2 Sheets-Sheet 2 Original Filed Jan. 11, 1962 THOMAS E. P\AZZE. $29M MM j g/M 9 United States Patent W and this application June 29, 1964, Ser. No. 378,765 7 Claims. (Cl. 229-57) This invention relates to receptacles and is more particularly concerned with improvements in bags which are formed from flexible plastic sheet materials.

This application is a division of application Serial No. 165,689, filed January 11, 1962, now Patent No. 3,150,573.

It is a general object of the invention to provide an improved bag structure wherein a flexible plastic sheet material is folded, sealed and cut so as to provide, when separated, a plurality of tubular bag forming sections with each section open at one end and closed at the other end by the folding or sealing operations so as to provide a square bottom formation.

It is a more specific object of the invention to provide a bag structure wherein a sheet of flexible bag making material is initially folded into flattened tube forming relation and the tube is divided into bag forming sections each with one end closed, each bag forming section is opened up on a mandrel and the closed end is reformed so as to provide the bag with a square bottom construction.

It is another object of the invention to provide a bag structure wherein a length of flattened tubular material is transversely sealed at one end and then opened up on a mandrel so as to permit additional seals to be made in the bottom forming material whereby to provide the bag with a square bottom construction.

It is still another object of the invention to provide a bag which is fabricated by forming flexible sheet material into tube-like sections with one end of each section flattened and closed by a transverse seam or fold, opening up each tubular section so as to provide a body portion having a rectangular crosss section and a bottom forming portion at the closed end of the tubular section having triangular end portions extending outwardly of oppositely disposed side walls, forming seals across the triangular portions at the bottom forming edges of the side walls so as to provide a square bottom, and removing the end portions which are outside of the sealed areas.

It is another object of the invention to provide a bag construction wherein a section of tubular material is formed which is closed across one end thereof, the tubular section is telescoped over an expansible mandrel, the mandrel is expanded and the tubular section is opened up so as to provide a body forming portion having a rectangular cross section and bottom forming portions at the closed end which are folded into a transverse plane at the end of the mandrel resulting in triangular folded portions extending in the plane of the bottom and laterally of oppositely disposed side faces of the mandrel, the triangular portions are sealed along the end edges of the mandrel side faces and the parts thereof which extend outside of the sealing lines are cut off thereby forming a square bottom.

It is a still further object of the invention to provide a bag construction wherein a length of tubular material is sealed transversely at one end thereof, the sealed tube is telescoped over an expansible mandrel, the mandrel is expanded and the body forming portion of the tube is opened up so as to provide a rectangular cross section and bottom forming portions adjacent the transverse seal are folded into a transverse plane at the end of the mandrel resulting in triangular folded portions extending in the 3,237,845 Patented Mar. 1, 1956 plane of the bottom and laterally of oppositely disposed side faces of the mandrel, the triangular portions are sealed along the bottom forming end edges of the side faces of the mandrel and finally the triangular portions which extend outside of the sealing lines are cut olf thereby forming a square bottom.

These and other objects and advantages of the invention will be apparent from a consideration of the several forms of the bag which are shown by way of illustration in the accompanying drawings wherein:

FIGURE 1 is a perspective view with portions broken away, illustrating the completed bag in opened up condition;

FIGURE 2 is a perspective view, with portions broken away, illustrating the completed bag in a flattened condition;

FIGURE 3 is a view showing the bottom end of a bag forming tube section which has been cross sealed and opened up on an expanded forming mandrel;

FIGURE 4 is a view showing the bottom end of a bag section after it has been flattened against the end of the forming mandrel and further sealed;

FIGURE 5 is a view showing the final cutting operation which completes the forming of the bag bottom;

FIGURE 6 is a fragmentary section taken one the line 66 of FIGURE 5 to a larger scale;

FIGURE 7 is a perspective view of a modified bag structure in opened up condition; and

FIGURE 8 is a perspective view of the bottom portion of the modified form of the bag in collapsed and flattened conditon, with the view being to a somewhat smaller scale.

The construction of the bag 10, which is illustrated in its completed and opened up condition in FIGURE 1, will be best understood by reference to the method employed in fabricating the same. The bag is formed'froma web of a suitable bag forming material such as a relatively thin film of polyethylene plastic. A continuous plastic web delivered from a supply roll or other source, is formed into a tube by a folding horn of conventional construction, and a longiutdinal seam is formed in the tube by joining overlapped marginal edge portions of the film. The flattened tube which is thus formed is provided with longitudinally spaced transverse seals 17. The flattened and sealed tube is severed adjacent the transverse seals 17 and divided into successive bag forming sections or lengths of equal size.

Each successive bag forming length or section is then telescoped onto one of a plurality of collapsed mandrels, each of which comprises a pair of rectangular plates which are moved apart or expanded after receiving the bag section by a suitable mechanism so as to open up the bag section.

The opening up of the bag section forms the body thereof into a rectangular cross section or shape with the bottom forming portion (FIGURE 3) automatically folding flat against the outside end of the mandrel so as to lie in a plane extending transversely of the long axis of the mandrel with folded triangular shaped end sections 26 and 26' extending outwardly of the sides of the mandrel. Transverse seals 27 and 27 (FIGURE 4) are formed across the folded sections 26 and 26 and the waste portions of the triangular sections 26 and 26' are then trimmed or cut off and discarded, leaving the bottom forming portions 25 of the bag in the form of a rectangle or a square bottom formation with the seal or seam formations 27 and 27' defining the bottom edges of the oppositely disposed side walls 30 and 30 which result from squaring up the body of the bag on the mandrel 22. The edge seals 27 and 27' project a slight distance outwardly of the bottom edges of the side walls 30 and 30' as shown in FIGURES 1 and 6.

If it is desired to store the bags for a period of time after they are removed from the forming mandrels, or if it is desired to accumulate a quantity of the bags in a stack, each bag may be collapsed and the bottom flattened as illustrated in FIGURE 2. This is most readily accomplished by simultaneously flattening the body of the bag and the bottom forming portion 25, the side walls 30, 30' and 35, 35 being flattened or collapsed so as to bring the longitudinal seam 13 along a center fold line in the side wall 35 which becomes the one edge 36 of the flattened body. The bottom forming portion 25 is folded into the plane of the one side wall 34 with the seam 17 extending in the direction of the long axis of the body of the bag and with the lower portions of the side walls 35 and 35' folding into the plane of the bottom portion 25 along fold lines 37, 3'7 and 38, 38' which extend from the ends of the seams 2'7, 27' to the ends of the edge folds 36 and 36'. The initially formed bottom side edge creases or folds 39 and 39' and the initial corner edge creases or folds 40 and 40 are indicated in dotted line in FIGURE 2.

A modified form of the bag is illustrated at 80 in FIGURES 7 and 8. The bag 80 is formed from a web of polyethylene film or similar plastic sheet material which is fed from a supply roll to a fol-ding bar which folds the web upon itself about a horizontal fold line 83 with the marginal edge portions of the film oflfset as shown so that one edge extends a short distance outwardly of the other edge 85. The flattened tube thus formed is cut and simultaneously sealed with a bead type seal 89 at longitudinally spaced intervals so as to divide the web into a plurality of bag forming sections,

.each of which has its side edges formed by head seals 89 and one end closed along the fold line 83.

Each successive bag section is advanced onto a mandrel, the mandrel is expanded and the bag bottom is formed in the same manner as described in connection with the bag 10. The bottom forming ortions 102 of the bag sections are squared up on the mandrel and the resultant triangular end portions are cross sealed by seal forming members so as to form bead seals 103 and 103' as shown in FIGURE 7 with the waste portions of the folded triangular members being cut away in the same manner as illustrated with respect to triangular members 26 and 26' in FIGURE 5.

If it is desired to collapse the bags 80 after they are removed from the forming mandrels they may be fiattened as illustrated in FIGURE 8. The body forming portion of the bag is collapsed so as to assume its original condition before expansion thereof on the forming mandrels. The side walls 104 and 104 and the end walls 105 and 105' are flattened so as to bring the bead seals 89 along the side edges of the body portion. The bottom forming portion 102 is folded about the bottom edge 106 of the one side wall 104' against the opposite side wall 104 which results in lower trianglar portions of the end walls folding into the plane of the bottom portion 102 along fold lines 107, 107' and 108, 108' which extend from the end seams 103 and 103 to the ends of the edge folds.

I claim:

1. A bag formed of heat scalable plastic film material comprising a body portion which, in the opened up condition, is in the form of a tubular section of substantially rectangular cross section with two pairs of oppositely disposed side walls and having a longitudinally extending heat sealed seam in the one side wall, and a bottom portion at one end of the body portion which includes a heat sealed bottom seam extending transversely of the longitudinal seam and having a length corresponding to the transverse dimension of one pair of the oppositely disposed side walls, and straight parallel heat sealed seams at opposite ends of said bottom seam which extend at right ngles to sai b t m seam and which are connected to the straight bottom edges of the other pair of side walls.

2. A bag formed from flexible plastic film material comprising a tube-like body portion and a bottom portion, said body portion having a rectangular cross section and said bottom portion having a rectangular shape when the bag is opened up with the edges thereof connected to the straight bottom edges of the body walls, said body portion having a longitudinally extending heat sealed seam in the center of one side wall thereof which extends into the bottom portion and said bottom portion having a heat sealed center seam extending across the end of said longitudinal seam and parallel with a pair of oppositely disposed body side walls, and parallel heat sealed end edge seams extending acoss opposite ends of said center seam which connect the bottom edges of the other pair of oppositely disposed body side walls to said bottom portion.

3. A bag formed of plastic sheet material which comprises, in empty flattened condition, two body forming wall members in face-to-face relation and connected along parallel side edge folds which extend from the mouth end of the body to a point near the bottom end with a longitudinal heat sealed seam extending along one of said side edge folds, and a substantially rectangular bottom integral with said body forming wall members and folded flat against bottom portions thereof, said bottom having a center heat sealed seam extending in one direction across the same and heat sealed end edge seams extending in the other direction, said bottom center seam being generally parallel with the side edge folds and midway between said side edge folds, and said end edge seams being parallel and disposed at the ends of said bottom center seam, said end edge seams each having its ends connected to a side edge fold by folds in the side wall members which extend in converging relation to a meeting point at the bottom end of a side edge fold.

4. A bag formed of plastic sheet material which comprises, when in empty collapsed condition, two body forming wall members in face-to-face relation and integrally connected along their parallel side edges by folds which extend from the mouth end of the body to a point near the bottom end with a longitudinal heat sealed seam extending along one of said side edge folds, and a substantially rectangular bottom having oppositely disposed edges integral with triangular folded bottom portions of said body forming wall members, said bottom having a center heat sealed seam extending across the same in a direction substantially parallel with said side edge folds and generally parallel heat sealed end edge seams extending across the ends of said bottom center seam, said end edge seams connecting the bottom with bottom edge portions of said body forming wall members which extend between said triangular folded bottom portions of said body forming wall members whereby when the bag is set up the side edge folds of the body forming wall members unfold and the body forming wall members open up to form two pairs of oppositely disposed body walls extending upwardly of the edges of the bottom, and each having a width corresponding to the dimension of the bottom edge from which it extends.

5. A bag which is fabricated from a section of a relatively thin, flexible, heat sealed plastic film, said film being initially formed into a flattened tube with heat sealed edges in the form of a bead, said bag when opened up having a rectangular bottom forming portion and a body forming portion of rectangular cross section with the bottom edges of the side walls joined along straight edges to the margins of the rectangular bottom forming portion and heat sealed seams extending across the bottom ends of two oppositely disposed parallel side walls so as to form two sides of said rectangular bottom forming portion.

6. A bag fabricated from a relatively thin, flexible plastic film material which is initially formed into an elongate tube, said bag comprising a tubular body portion and a square bottom closing one end thereof, which square bottom includes heat sealed seams in the form of an H with two oppositely disposed side edges formed by straight narrow fiat seams extending outwardly of the bag walls.

7. A bag which is fabricated from a section of a relatively thin, flexible, heat sealed plastic web which is initially formed into a tube with overlapping edge portions connected by a longitudinally extending fiat, heat sealed seam, said bag having a rectangular bottom forming portion with a transversely extending, fiat, heat sealed seam extending across the end of the longitudinal seam in a direction normal thereto and a pair of straight parallel, flat, heat sealed seams extendiing across opposite ends of said transverse seams in a direction normal thereto so as to define two edges of said bottom forming portion.

References Cited by the Examiner UNITED STATES PATENTS 2,149,872 3/1939 Schmidt 22958 2,821,337 1/1958 Morgan 22957 3,136,475 6/1964 Geimer 22957 3,143,277 8/1964 La Fleur 22957 FOREIGN PATENTS 1,055,074 10/1953 France.

GEORGE o. RALSTON, Primary Examiner.

FRANKLIN T. GARRETT, Examiner. 

4. A BAG FORMED OF PLASTIC SHEET MATERIAL WHICH COMPRISES, WHEN IN EMPTY COLLAPSED CONDITION, TWO BODY FORMING WALL MEMBERS IN FACE-TO-FACE RELATION AND INTEGRALLY CONNECTED ALONG THEIR PARALLEL SIDE EDGES BY FOLDS WHICH EXTEND FROM THE MOUTH END OF THE BODY TO A POINT NEAR THE BOTTOM END WITH A LONGITUDINAL HEAT SEALED SEAM EXTENDING ALONG ONE OF SAID SIDE EDGE FOLDS, AND A SUBSTANTIALLY RECTANGULAR BOTTOM HAVING OPPOSITELY DISPOSED EDGES INTEGRAL WITH TRIANGULAR FOLDED BOTTOM PORTIONS OF SAID BODY FORMING WALL MEMBERS, SAID BOTTOM HAVING A CENTER HEAT SEALED SEAM EXTENDING ACROSS THE SAME IN A DIRECTION SUBSTANTIALLY PARALLEL WITH SAID SIDE EDGE FOLDS AND GENERALLY PARALLEL HEAT SEALED END EDGE SEAMS EXTENDING ACROSS THE ENDS AT SAID BOTTOM CENTER SEAM, SAID END EDGE SEAM CONNECTING THE BOTTOM WITH BOTTOM EDGE PORTIONS OF SAID BODY FORMING WALL MEMBERS WHICH EXTEND BETWEEN SAID TRIANGULAR FOLDED BOTTOM PORTIONS OF SAID BODY FORMING WALL MEMBERS WHEREBY WHEN THE BAG IS SET UP THE SIDE EDGE FOLDS OF THE BODY FORMING WALL MEMBERS UNFOLD AND THE BODY FORMING WALL MEMBERS OPEN UP TO FORM TWO PAIRS OF OPPOSITELY DISPOSED BODY WALLS EXTENDING UPWARDLY OF THE EDGES OF THE BOTTOM, AND EACH HAVING A WIDTH CORRESPONDING TO THE DIMENSION OF THE BOTTOM EDGE FROM WHICH IT EXTENDS. 